JPS618210A - Noise suppressing structure for rotary hydraulic cylinder for chuck - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a structure that is particularly effective in reducing the operating noise of a rotary fluid pressure cylinder used in the chuck of a machine tool when it is attempted to operate during operation. This is a proposal.

The present applicant has previously proposed several such rotary hydraulic cylinders, and the present invention relates to improvements thereto.

A specific example of implementation will be described below based on the drawings.

In Fig. 1, 1 is a cylinder, 2 is a piston rod, and 3 is a cylinder.
is a piston fixed on the piston rod 2,
It is slidably fitted into the cavity 4 of the cylinder 1. 5
is a rotary valve that is fitted into the piston rod 2, and a mechanism 6.6' that locks the flow of oil is provided in a part of the spigot.
is assembled and connected to the cylinder 1 using bolts 7. 8.9.10 is an O-ring to maintain airtightness.

Reference numeral 11 denotes a guide pin fixed to the piston 3, and either end P or P' of the guide pin is always guided into a guide pin hole 12 provided in the cylinder 1 or the rotary valve 5 (in the illustrated example, on the cylinder side). As a result, free rotation of the piston rod 2 is restricted.

In the illustrated example, a threaded portion at the end of the piston rod 2 is connected to the draw tube, and is configured to move the jaw (none of which is shown) of the chuck body.

On the other hand, the rotary valve 5 has a two-stage lock-like external shape with A, KZ
A sleeve body 13 is provided at the lower stage. Here, inside the sleeve body 13 is the sleeve 1.
4 is provided as follows.

That is, the bearings 15 fitted into both ends of the sleeve 14.
15' (15 in the illustrated example) directly connects to the sleeve 14.
is in contact with the inner wall of the other bearing (1 in the illustrated example).
5') is adapted to be brought into contact with the inner wall of the sleeve cover 17 which is joined to the sleeve body 13 by the bolt 16. Further, a stopper 18 is fixed to the edge of the lower part using bolts 9, and a concave-convex shape having a labyrinth reel structure is formed between the two facing the sleeve cover. However, oil that enters from the outside can be removed from the oil drain groove 20.
In contrast, hydraulic oil leaking from the inside is collected into a drain reservoir 22 within the sleeve body 13 through an oil drain groove 21. At this time, the sleeve cover 17 is provided with an air plug 23 in order to easily and reliably separate and distinguish the discharge and recovery.

Next, the operation of the piston 3 within the cylinder 1 will be explained as follows.
This is done as follows. External supply device (not shown)
Hydraulic oil from the oil tank is supplied to the oil filler port 24 of the sleeve body 13.
The oil passage 26 passes through the oil passage 25 through the lock mechanism 6,
The oil is guided to the oil chamber 27, and the piston 3 is moved from the right side to the left side in the drawing. The drain oil in the oil chamber 27' that is pushed out as the piston 3 moves passes through the lock mechanism 6', the oil passage 25', and is collected from the oil drain pipe 24' to an external supply device.

When the forward stroke of the piston as described above is completed and the piston moves to the backward stroke, a switching valve (not shown) is switched so that the above-mentioned wandering oil pipe 24' becomes the oil supply pipe, and the oil supply pipe 24 becomes the oil drain port. The reverse process is performed using a similar reverse path circuit.

At this time, a small amount of hydraulic oil is supplied to the bearings 15.15' on both sides through the gaps T and T' between the rotary valve 5 and the sleeve I4, and after lubricating the bearings 15.15', it is supplied to the outside via the drain reservoir 22. Collected into equipment (oil tank). At this time, since there is a communication hole inside the sleeve 14, the amount of oil supplied to both bearings 15, 15' is kept balanced.

The hydraulic oil circuit described above allows a workpiece that is not a part to be grasped at hand, and machining of the workpiece is performed.

When machining such a workpiece, if an attempt is made to grip and release the workpiece without stopping the rotation of the chuck during operation, conventional machines generate operating noise and vibration from the rotary joint, resulting in poor machining accuracy. Problems such as these were occurring.

The present invention prevents the occurrence of this vibration by devising the rotary joint, and is particularly effective in reducing operating noise.

Next, improvements to the rotary joint section will be explained with reference to FIGS. 2 and 3. 2 is a sectional view taken along line 2 in FIG. 1, and FIG. 3 is a perspective view of the sleeve 14. As is clear from the figure, the sleeve 14 is provided with one annular oil passage 25a and one annular oil passage 25'a around the entire circumference, and a large number (in the figure, each annular oil passage 6 locations) oil passages 25b and 25'
b are perforated radially. Then, the oil passage is opened in correspondence with one or more openings of the oil passage,
A plurality of oil passage reservoirs 2 are cut into the outer periphery of the rotary valve 5.
5c, 25c, . The oil passages 25 (25'> 2 locations are shown) are in communication with each other (in the example shown in FIG. 2, three oil passages 25c (25'c) and three oil passages 25(25') are connected to each other).

The seal members R1, R2, and R3 are O-rings for preventing oil leakage from the oil passages 25a and 25a', and the sleeve body 13 and the sleeve 14 are fixedly fixed in a non-rotatable state by a set screw U. Sleeve body 13 and sleeve 1
4 by shrink fitting, use the O-rings R1 and R2.
, R3 and the set screw 11 can be omitted to provide a compact structure. Note that the sleeve body 13 may be provided with grooves for the oil passages 25a, 25'a and the seal materials R1, R2, and R3.

However, the hydraulic oil supplied through the inlet 24 passes through the annular oil passage 25a and is guided to the oil passage reservoir 25c via one of the many oil passages 25b, 25b, and so on. It is sent to route 25.

On the other hand, the waste oil pushed out to the oil passage 25' is transferred to the oil passage sump 25.
'c, and then a number of oil passages 25'b, 25'b・
The oil is returned to the annular oil passage 25'a through one of the oil passages, and is collected into the oil tank via the oil drain port 24'.

In this case, since the rotary valve 5 is rotating, the oil passage reservoir 25
c, 25' In order to prevent sudden opening and closing actions between c and oil passages 25b and 25'b, the groove width is narrower than that of oil passages ffl 25 e and 25'C as shown in Fig. 4. The grooves A and A' communicate each of the oil passages 25b and 25'b.

According to the results of the applicant's measurement of noise using a simple sound level meter at a distance of one foot using the rotating fluid pressure cylinder constructed as described above, the one without grooves A and A' has a noise level of 85 dB (A).
Grooves A and A' have a groove width of lllll11 and a depth of 1■78
It was dB(A). Increase the chuck rotation speed by 1 more during measurement.
If you record the measurement results when increasing the rpm by 1000 rpm, groove A
, 92 dB (A) for those without A', 85 dB (A) for those with grooves A and A' width lllll 11 and depth 0.3.
, grooves A and A' with groove di 1 + am depth 1■ are 8
It was 0 dB(A). (However, the inner diameter of the sleeve 14 is 70 m, and the oil passage 25b has a diameter of 6 cm and is provided at 6 locations around the circumference.) In this case, the shapes of the grooves A and A' were approximately rectangular in cross section. , or any other geometrical shape may be used as long as it is preferable for reducing noise from the viewpoint of fluid dynamics.

As is clear from the above explanation, by providing the grooves A and A', the grasping and releasing operation of the chuck (not shown) can be carried out without stopping the rotation of the chuck, even during its operation, without any problem. Moreover, it has become extremely effective in reducing operating noise.

In the above explanation, the grooves A and A' were explained as being provided on the sleeve 14 side, but mB and B' are cut on the opposite rotary valve 5 side and communicate the oil passage reservoirs 25G and 25'C.
It may also consist of: In this case, the sleeve 14 side is not provided with the grooves A and A'.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the rotary fluid pressure cylinder, FIG. 2 is a sectional view taken along the Z-Z line in FIG. 1, FIG. 3 is a perspective view of the sleeve 14, and FIG.
The figure is an enlarged view of the intersection of the oil passage and the groove.

Claims (1)

[Claims] A rotary fluid pressure cylinder in which a rotary body with a built-in reciprocating piston is inserted through a hydraulic oil supply body into which an oil passage block is inserted, and the oil passage block has an annular shape provided on the outer periphery of the block. A plurality of oil passages are provided to communicate with the oil passage in a radial manner, and openings of the plurality of oil passages are at least once connected to a plurality of oil passage reservoirs cut in front of a part of the rotating body. In a rotary fluid pressure cylinder that communicates with more than one location,
A low-noise structure for a rotary fluid pressure cylinder for a chuck, characterized in that a plurality of radial oil passages are connected by a groove narrower than the groove width of an oil passage sump.